The vast majority of gay men, HIV-positive and negative, make some effort to moderate their risk of transmitting or acquiring HIV, a large Australian study finds.
Dr Limin Mao of the University of New South Wales in Australia, speaking at the Tenth AIDS Impact conference, said that the results of three annual surveys show that the decisions faced by gay men are much more complex than the decision whether or not to use a condom. Choices range, in terms of the likely degree of protection from HIV they offer, from avoiding sex or anal sex altogether to merely avoiding unprotected anal sex with someone known to have the opposite HIV status.
Using condoms 100% of the time for anal sex is still the most popular single strategy, the study found, but only a third of HIV-negative men and a quarter of HIV-positive men now do this. Taken as a whole, strategies involving basing whether to have unprotected anal sex on a partner's HIV status (serosorting) are now at least as popular as 100% condom use regardless of HIV status.
The study found a clear difference between serosorting practices according to participants' HIV status. The second most popular safer-sex strategy for HIV-negative men was to restrict unprotected sex to an HIV-negative regular partner – a strategy that has been called 'negotiated safety'.
HIV-positive men were less likely to restrict unprotected sex solely to their primary partner; instead the most popular strategies were to limit unprotected anal sex, both with regular and casual partners, to other HIV-positive partners – or at least to try and exclude having it with regular and casual partners not known to be HIV positive.
The study involved three successive Gay Community Periodic Surveys which took place in eight metropolitan locations in Australia between 2007 and 2009. There were 16,375 participants. Ninety per cent reported being HIV negative at the time of the survey, and of the one in ten men with HIV, 70% reported their viral load as undetectable.
Importantly, these results exclude 3273 men (about 17% of all survey participants) who were either untested for HIV or did not know their status, or who were HIV positive but did not know their viral load. So it tells us nothing about the risk avoidance strategies of untested men.
Before now, national and international surveys have asked gay men whether they use condoms and, more recently, about their and their partners' HIV status. But this survey also asked whether, in the previous six months, the respondents' safer-sex behaviour was different between regular or casual partners; and it divided the HIV-positive men into those with an undetectable and detectable viral load.
One hundred per cent condom use was still the most popular single strategy, but a minority one, being practised by 33.8% of the HIV-negative men, 25.5% of HIV-positive men with an undetectable viral load and 22.5% of HIV-positive men with a detectable viral load.
The second most popular choice for HIV-negative men was negotiated safety with regular partners, and 100% condom use with casual ones. One in five HIV-negative men restricted unprotected anal intercourse (UAI) to a regular partner definitely known to be negative.
In addition 7.5% had UAI with regular partners not known to be positive – a 'safe only if non-concordant' strategy. This may mean HIV status has not been discussed in the relationship, or it has been discussed but the partner's status is not known; it leaves room for partners to have HIV but either not know it or not disclose it.
This means that altogether, about a quarter of HIV-negative men were attempting to serosort, or at least make choices based on HIV status in some way, with regular partners, but maintaining condom use with casual partners. The third most popular choice for HIV-negative men was to avoid having anal sex at all. About one in eight did this, while one in nine went to the other end of the spectrum and attempted to base condom use on what they knew about the HIV status of casual as well as regular partners.
The situation with HIV-positive men was different. After 100% condom use, their preferred sexual harm reduction strategy was to base condom use on what they knew about the HIV status of casual as well as regular partners. This probably reflects the fact that an HIV-positive man can always volunteer or ask for a definite piece of data whereas being HIV-negative is only known till the last test.
Fourteen per cent of positive men with undetectable viral loads and 19% of men with detectable ones had UAI with regular partners (of any status) and with casual partners they knew to have HIV. And there was soem evidence that 19% of undetectable men and 22% of detectable ones were attempting a 'safe if non-concordant' strategy, that is to say not ensuring they had protected sex unless they knew or suspected their partner was HIV negative. However in the paper published on this study, this was decribed as "unprotected anal intercourse with some status disclosure", implying that a high proportion of partners' status was unknown and that it many cases status simply wasn't discussed..
Taken together, this means that attempting to restict unprotected sex to partners of known or assumed HIV-positive status, with both regular and casual partners, was by some way the most popular sexual harm reduction strategy in HIV-positive men, being practised by 32.5% of undetectable men and 41.1% of men with detectable virus as opposed to 11% of HIV negative men. However this strategy was often appled haphazardly..
In contrast only 12% of HIV-positive men who were undetectable and 10% who were detectable adopted the negative men's favourite serosorting strategy of restricting unprotected sex to regular partners.
This left three minority categories. About 6% of men in each category had been celibate over the last six months and had had no sex at all. About one in 12 men in each category had no harm reduction strategy and had UAI with partners regardless of status, even when they knew partners had the opposite HIV status.: it was notable that this was as common in HIV-negative men as it was in undetectable HIV-positive men, though somewhat rarer (about one in 17 men) in men with detectable viral loads. This could reflect some 'viral sorting'. And finally 4% of the positive men and only 1% of the negative men maintained condom use with casual partners but had unprotected sex with a partner known to have the opposite HIV status.
As well as viral sorting, there was also some evidence of other strategies such as 'seropositioning' (taking the role less likely to transmit HIV, i.e. positive men taking the receptive role and negative men the insertive one) and withdrawal before ejaculation, though data on these were not presented at AIDS Impact.
A challenge for health educators
Dr Mao commented that gay men usually seemed to stick to their chosen strategy quite consistently; the decision to have unprotected sex or use a condom was not taken capriciously but was in line with the degree of risk each man felt happy with.
The fact that gay men were adopting such a variety of different harm reduction approaches posed a challenge to health educators used to promoting a one-size-fits-all safer-sex approach.
Mao LM et al. Rates of condom- and non-condom-based anal intercourse practices among homosexually active men in Australia: deliberate HIV risk reduction? Tenth AIDSImpact conference, Santa Fe, New Mexico, abstract 15, 2011.
Mao LM et al. Rates of condom and non-condom-based anal intercourse practices among homosexually active men in Australia: deliberate HIV risk reduction? Sexually Transmitted Infections 87:489-493. 2011.